Analysis of DNA base sequences in the human genome (entire gene information) has been nearly completed and future research tasks have shifted to elucidating functions of the genes encoded by DNA. Much of gene information encoded by the DNA relates to proteins, and the research to elucidate the functions of the genes by demonstrating structures, functions and roles of the proteins have been performed in various research institutions.
Many proteins are expressed based on the genetic information in vivo, and vital activity is maintained by interaction of those proteins. For example, in a citric acid cycle which is a typical metabolic pathway in cells, pyruvic acid is decomposed by interactions of a plurality of enzymes (proteins) to supply energy for producing ATP.
Many of the diseases caused in vivo are believed to occur by producing abnormalities in the interaction between the proteins in the cells. For example, in the case of genetic diseases, the normal protein is not expressed, and thus, the necessary interaction between the proteins is absent or the abnormality occurs in the interaction between the proteins to cause a metabolic abnormality, and they result in generating the disease.
Therefore, concerning various proteins expressed in vivo, it is important to elucidate a reaction pathway in the cells or to reveal the function and the role of the protein in order to reveal the interaction between the proteins. By revealing the interaction between the proteins, it is possible to provide the information effective for elucidating onset mechanisms of various diseases or developing the therapeutic agent.
Here, four proteins, i.e., proteasome, ubiquitin, ZNF216 and AWP1 which are associated with the present invention will be described.
Proteasome is a macromolecular protease (proteolytic enzyme) localized in nuclei and cytoplasm and a protein with a molecular weight of 700,000 to 800,000 composed of 28 subunits. “26S Proteasome” obtained by binding PA70 (activation factor) to both ends of proteasome has the function to decompose the protein depending on ATP, and plays a main role in a ubiquitin/proteasome proteolytic system. 26S Proteasome selectively decomposes the protein polyubiquitinated (modified with a polyubiquitin chain) (Non-patent Document 1).
Proteasome is also involved in the occurrence mechanism of the disuse muscular atrophy (Non-patent Documents 2 and 3). The disuse muscular atrophy refers to reduced muscular size and lowered muscular force when a bedridden state continues and the state of not using muscles persists. It is thought that muscular size is reduced to cause the disease when the state of not using muscles persists because the proteins such as myosin which compose muscles are decomposed in the ubiquitin/proteasome proteolytic system.
Ubiquitin is a protein composed of 76 amino acids which is universally present in eukaryotic cells, and has the role to label the protein to be decomposed (target protein) in the ubiquitin/proteasome proteolytic system. In the ubiquitin/proteasome proteolytic system, the polyubiquitin chain plays the role to label the target protein. The polyubiquitin chain is formed by binding a large number of ubiquitin in a branched shape, and is bound to a particular site of the target protein. When the polyubiquitin chain is bound to the target protein, 26S proteasome recognizes the target protein and decomposes the target protein (see Non-patent document 1).
ZNF216 is a protein whose gene was identified as a zinc finger protein by D. A. Scot et al. in 1998 (Non-patent Document 4). AWP1 is a novel protein isolated by W. Duan et al. in 2000 (Non-patent Document 5). Specific functions and roles in vivo in both proteins are still unknown.
Non-patent Document 1: “Jikken Igaku” Vol. 21, No. 3, pp 330-332, February, 2003, Yodosha.
Non-patent Document 2: Gomes et al “Atrogin-1, a muscle-specific F-box protein highly expressed during muscle atrophy”, Proc. Natl. Acad. Sci. USA, 2000, Vol. 98, No. 25, pp 14440-14445
Non-patent Document 3: Bodine et al “Identification of ubiquitin ligases required for skeletal muscle atrophy”, Science, 2001, Vol. 294, pp 1704-1708
Non-patent Document 4: D. A. Ccott et al “Identification and mutation analysis of a cochlear-expressed, zinc finger protein gene at the DFNB7/11 and dn hearing-loss-loci on human chromosome 9q and mouse chromosome 19”, AN INTERNATIONAL JOURNAL ON GENES AND GENOMES, Elsevier Science B.V., 1998, p 461-469Non-patent Document 5: W. Duan et al “Cloning and characterization of AWP1, a novel protein that associates with serine/threonine kinase PRK1 in vivo”, AN INTERNATIONAL JOURNAL ON GENES, GENOMES AND EVOLUTION, Elsevier Science B.V., 2000, p 113-121.